import React, { Component } from 'react'

export default class Demo extends Component {
    state = { count: 0 }

    add = () => {
        //对象式的setState
       /*  // 1.获取原来的count值
        const { count } = this.state;
        // 2.更新状态
        this.setState({ count: count + 1 }, () => {
            console.log( this.state.count);
        })
        console.log( this.state.count); */
        
        //函数式的setState
        this.setState((state, props) => {
            console.log(state, props);
            return {count:state.count+1}
        },() => {
            console.log( this.state.count);
        })
    }

    render() {
        return (
            <div>
                <h1>当前求和为：{ this.state.count }</h1>
                <button onClick={this.add}>点位加1</button>
            </div>
        )
    }
}
